The spread across the Internet of several versions of the malicious program Duqu has become a main news item in the IT Security industry. In no small part, this is due to some similarities between this new worm and last year's infamous Stuxnet worm. What is alarming in this case however is that the ultimate objective of Duqu remains unknown. Anti-malware experts at Kaspersky Lab have carried out their analysis of the new malware, the main findings of which are as follows. The Duqu worm was first detected in early September 2011, after a user in Hungary uploaded one of the components of the malicious software to the Virustotal website, which analyses infected files with anti-virus programs of different manufacturers (including Kaspersky Lab's). However, this first-detected sample of Duqu turned out to be just one of several components that make up the whole of the worm. A little later, in a similar way, the Kaspersky Lab anti-malware experts received a sample of another module of the worm via Virustotal, and it was specifically its analysis that permitted finding a resemblance with Stuxnet. Though there are some overall similarities between the two worms Duqu and Stuxnet, there are also significant differences. [...]